德兴矿区土壤中铜的地球化学形态及影响因素  

GEOCHEMICAL SPECIATION AND AFFACTING FACTORS OF COPPER IN THE SOIL IN DEXING MINGING AREA

作　　者：滕彦国[1] 刘晶[1] 崔艳芳[1] 王金生[1] 

机构地区：[1]北京师范大学水科学研究院水沙科学教育部重点实验室,北京100875

出　　处：《矿物岩石》2007年第2期59-63,共5页Mineralogy and Petrology

基　　金：国家自然科学基金项目(40603017);科技部国际科技合作计划重点项目(2005DFA20900)

摘　　要：土壤中铜的地球化学形态决定了其在环境中的释放、变化形式、迁移规律及生物效应。通过对德兴铜矿及周边地区82件表层土壤样品,采用改进的BCR提取方法测定铜的地球化学形态,了解其区域分布特征,结果表明:(1)德兴地区土壤中酸可溶态的铜≈可还原态铜<可氧化态铜≈残渣态铜,酸可溶态+可氧化态+可还原态的铜平均质量分数为45.07×10-6,较中国土壤背景值全铜的质量分数(22.6×10-6)高,这些活动态的铜易于进入食物链,对人体健康和生态安全构成潜在的威胁,不同形态铜的区域分布特征相似,主要位于采矿和选矿活动区附近;(2)采用改进的BCR方法提取的土壤中铜的酸可溶态和可氧化态和采用EDTA提取的可交换态具有明显的正相关关系,土壤pH值增大时酸可溶态铜的比例降低,土壤TOC含量增加时可氧化态铜的比例增大,而土壤CEC对BCR方法提取铜的形态影响不大。Releasing, changeable forms, migration and biological effects of copper were controlled by its geochemical speciation in the soil. A total of 82 topsoil samples were collected around Dexing mining area and by improved BCR extraction procedure, the geochemical forms of copper were studied. In addition, the regional patterns of geochemical speciation and influence factors of copper were discussed. The geochemical speciation of copper was acid soluble ≈ reducible 〈 oxidisable residual in Dexing mining area,and the average of the three forms of acid soluble, reducible, and oxidisable was 45.07 × 10 ^-6 which was higher than the total copper in China soil background. These three forms of copper were geochemically mobile and easy to enter into food-chain to threaten human health and ecological safety. There were similar distributed patterns of copper speciation,and the abnormal sites were located in and around mining and extracting area. There was a significant relationship between acid soluble fraction and oxidisable fraction by improvement of BCR extraction procedure and exchangeable fraction by EDTA extraction. Some factors influenced fractionation of copper in the soil by improved BCR extraction procedure, acid soluble copper decreased when pH increased, oxidisable copper increased when TOC content increased, while the impact of soil CEC on copper fractionation was weak.

关 键 词：铜 化学形态 地球化学活动性 BCR影响因素 

分 类 号：P595[天文地球—地球化学] X53[天文地球—地质学]